Why are 80% of kids in Singapore nearsighted? Perhaps it’s a nature-deficit disorder.

Singapore has one of the highest rates of nearsightedness or myopia in the world, and parts of China and Taiwan are not far behind.

Most people assume it’s just genetics.

And there’s certainly a lot of evidence suggesting a genetic link. In Australia, for example, if both parents have myopia, a child is eight times as likely to have it as well, and if both parents have severe myopia (at least -6 diopter), a child is 22 times as likely (Ip et al. 2007).

People of Chinese origins are particularly prone to myopia (Pan et al. 2012).

But here’s the Singapore twist. The city-state is a melting pot of Chinese, Indian and Malay ethnicities. Yet Singapore has a far higher myopia prevalence rate than India or Malaysia and a slightly higher rate than China.

Genetics almost certainly plays a role in myopia, but families generally share not only genes but also environments.

While our genetic DNA in “pen” and cannot be changed, some of our genes are written in “pencil” and can be rewritten by environmental factors.

Worldwide, there’s an urban-rural divide in myopia rates. In Nepal, for example, urban children age 15 have a 27% prevalence rate while it is less than 3% for rural children the same age (Pan et al. 2012).

Enjoy Osprey Cam Live!

The Ospreys Are Back!
Live views, 24/7, of an Alabama osprey nest. Record your observations and ask our ecologist about what you’re seeing.

What is Cool Green Science?

noun1. Blog where Nature Conservancy scientists, science writers and external experts discuss and debate how conservation can meet the challenges of a 9 billion + planet.

2. Blog with astonishing photos, videos and dispatches of Nature Conservancy science in the field.

3. Home of Weird Nature, The Cooler, Quick Study, Traveling Naturalist and other amazing features.

Cool Green Science is edited by Matt Miller, the Conservancy's deputy director for science communications, and managed by Lisa Feldkamp, an American Council of Learned Societies fellow with the TNC science communications team. Email us your feedback.